1. Field of the Invention
The present invention relates to a bar storage apparatus for storing bars to be supplied to a bar processing machine such as a sawing machine, and more specifically to a bar storage apparatus capable of storing a great number of bars of various sorts and further of facilitating conveyance of any required bars into and out of the bar processing machine.
2. Description of the Prior Art
As the prior arts related to the present invention, there are such documents as U.S. Pat. No. 4, 362, 454; Laid-Open German Patent No. DE 4, 018,139-A1; and PCT/JP92/00061 (filed by the same Applicant).
In prior art bar storage apparatuses for storing various bars to be supplied to the bar processing machine such as the sawing machine, as disclosed in the above-mentioned documents, a roller conveyer is arranged on the rear side of the bar processing machine; and a chain conveyer is disposed along a direction perpendicular to the bar feeding direction of the roller conveyer; and bars to be processed are mounted on the chain conveyer in accordance with the order of processing.
In the above-mentioned construction, when the chain conveyer is driven, bars mounted on the chain conveyer are conveyed in sequence onto the roller conveyer, and further into the bar processing machine by the roller conveyer, so that it is possible to realize an unmanned bar processing system.
In the prior art construction as described above, however, since bars must be mounted previously on the chain conveyer in sequence, and further the arrangement of bars is of two-dimensional way (which is because bars are arranged on the chain conveyer), there exists a problem in that it is difficult to store a great number of bars.
To overcome the above-mentioned problem, a construction for storing bars in three-dimensional way has been proposed.
In the prior art construction for storing bars in three-dimensional way, however, since bars are directly mounted on each of a plurality of shelves, bars must be conveyed into and out of the respective shelves by use of a conveying machine such as a ceiling crane or a gantry crane. Consequently, in the above-mentioned prior art construction, although a great number of bars can be stored, there exists another problem in that the whole construction is large in size and further it take a relatively long time to convey bars to and from the bar processing machine.